Radiator core



April 12, 1949. H. w. CASE RADIATOR CDRE Filed April 18, 1945 1M 'liN10R. b29040 #461485 Patented Apr. 12,1949

UNITED STATES PATENT OFFICE 2,466,684 n RADIATOR CORE Harold W. Case,Dayton, Ohio Application April 18, 1945, Serial No. 589,005

(Granted under the act of March 3, 1883, as amended April 30, 1928; 3700. G. 757) 2 Claims.

-'Ihe invention described herein may be manufactured and used by or forthe Government for governmental purposes, without the payment to me ofany royalty thereon.

This invention relates to radiator core tubes and particularly to thetubes of radiator cores through which the cooling medium travels atextremely high speed, as it does for instance in the radiators of highspeed aircraft, the improvement in subject invention being particularlyconcerned with the mounting sleeves of such tubes.

In my prior Patent No. 2,325,036, of July 27, 1943, I show and describea radiator core made up of Venturi-shaped tubes, the Venturi shape beingsuch that if a section is taken through the core on a plane which passesthrough the axis of two adjacent tubes, the section formed by the lowersurface of the upper tube and the upper surface of the lower tube willbe substantially that .of a symmetrical airfoil. This section variesfrom a true symmetrical airfoil in that the chord line of the uppercontour is separated slightly from the chord line of the lower contour.

The mounting sleeves of the tubes disclosed in the prior patent supra,however, were so made and formed as to leave relatively blunt ends frontand back on the airfoil shape above mentioned, thereby retarding theentry and exit of the airflow through the core.

It is therefore an object of this invention to substantially follow theteaching in the prior patent, supra, insofar as the tubes are of suchVenturi shape that the section formed by the lower surface of the uppertube and the upper surface of the lower tube follows the form .of a truesymmetrical airfoil. In the section of the present invention the chordlines of the upper and lower contours are one and the same. It is alsothe object of this invention to so alter and improve the mountingsleeves that the said true symmetrical airfoil shapes come tosubstantially a sharp edge both front and back, to the end that theremay be both a smoother entry and a smoother exit forthe cooling airpassing through the radiator whereby the volume of air passing throughthe core in a given time will be increased.

More generally the object of my invention is to provide a radiator coretube which will ofler the smallest possible resistance to'the passage ofair at a given speed, by so forming the tube that the air moving throughthe tube will be passing around a true symmetrical airfoil section whichhas characteristics proportionate to the speed for which the radiator isdesigned.

Still another object is to so fashion the mounthad to the drawing,wherein:

Fig. 1 is an axial section through one of my im proved radiator coretubes.

Fig. 2 is an end view of a section of a radiator incorporating aplurality of these tubes.

Fig. 3 is a cross-sectional elevation through a row of tubes taken onthe line 3-3 of Fig. 2.

v Fig. 4 is a transverse section taken at 4-4 of Fig. 3.

Like reference characters refer to like parts Lhroughout the severalviews.

The axial cross section Fig. 1 shows a single tube l of Venturi shape,the throat of which,.in the instant case, is at l3, which may besomewhere near the midway point of its length. The cross section of themain portion of the tube shown is circular both outside and inside butof varying dimensions throughout the length, while the end sleeves 2 arehexagonal on the outside a and of uniform external dimensions throughouttheir length, the inside diameter being flared outwardly graduallymerging from round to hexagonal as at IS, the internal and externalhexagonal contours meeting in a sharp edge at the end of the tube as atH and I2 where the inner contour and the outer contour substantiallycoincide.

Fig. 2 shows the end view of asection of a radiator incorporating aplurality of these tub'es. After assembling the tubes together as shownin this figure, they are soldered at the ends in the same manner asconventional radiator core tubes; i. e., by dipping in molten solderwhile held in a clamp.

In Fig. 3 the cross-sectional elevation through a. row of tubes taken onthe line 3-3 of Fig. 2, the section formed by the contours 8 and 9represent: ing the lower and upper wetted air surfaces of the walls oftwo adjacent core tubes, such as land Ill, respectively, on said plane,will conform to the shape of a true symmetrical airfoil havingextremities both front and back terminating in sharp edges as at H and[5. The thickest section of the airfoil is on line l3. The cooling airproceeds through the center of the tubes as shown by the arrows 3 and 4,while the fluid to be cooled is circulated around the core tubes in thespaces 5 between adjacent tubes. The line 6-1 represents the chord ofthe airfoil section which is described as being the lower and upperwetted air surfaces of the walls of core tubes I and I0, re-

spectively. If the upper contour 8 of the airfoil having the line -1 asits chord is rotated about the axis :r-v, which is substantiallyparallel to the chord but displaced therefrom on the convex side of thecontour 8, the surface thus generated will have the form of aVenturi-shaped tube which constitutes the wall of radiator core tube Iin Fig. 3. If the lower contour 9 of the airfoil having the same line8-4 as its chord is rotated about the axis z'-y', the surface thusgenerated will constitute the wall or core tube in. The wetted" aircontours 8 and 9 representing the lower and upper sections of core tubesl and I0, respectively, are symmetrical about their common chord 6-1.Consequently, the air which passes through the two tubes I and I 0 flowsaround a true symmetrical airfoil and the wind resistance of the twotubes is equivalent to that of a true symmetrical airfoil section.

In the single embodiment of my invention whichI have shown anddescribed, I have suggested the use of round tubing with the endsbrought to hexagonal shape, but it will be obvious that the ends couldbe square or triangular and that the tubing could be hexagonal, squareor of other suitable cross section.

Moreover, in the embodiment selected for illustration, I have showncertain curves as at 8 and 9 of Fig. 3 to define the shape of theairfoil, but it will be obvious that the section of the airfoil whichwill offer minimum resistance in any particular case will depend uponthe speed at which the radiator core is to be used.

Having thus described an embodiment of my invention, I claim:

1. A radiator core composed of a plurality of elements, each comprisinga Venturi-shaped tube which flares from the throat outwardly toward theends, mounting portions at the ends of the tubes being externally shapedto uniform prismatic contour throughout their length, theinside contourof the tubes being so shaped and flared that the inside and outsidecontours come into exact coincidence in a sharp edge at the end of thetube, so that when the tubesare laid with their mounting sleeves uponeach other, the section formed by the lower inside contour of the uppertube and the upper inside contour of the lower tube, when viewed at asection formed by a plane passing through the axis of the two tubes,will have the form of a true airfoil section with symmetrical upper andlower contours meeting their common chord at the ends of the tubes.

2. A radiator core composed of a plurality of elements, each comprisinga Venturi-shaped tube which flares from the throat outwardly toward theends, mounting portions at the ends of the tubes being externally shapedto uniform prismatic contour throughout their length, the inside contourof the tubes being so shaped and flared that the inside and outsidecontours come into exact coincidence in a sharp edge at the end of thetube, so that when the mounting sleeves are held together at both endsoi the tubes, the cooling air which flows through the core tubes willflow around symmetrical airfoil sections which have their upper andlower contours meeting their common chords at the ends of the tubes.

HAROLD W. CASE.

REFERENCES CITED The following references are of record in the file ofthis patent:.

UNITED STATES PATENTS I Number Name Date 1,713,020 Browne May 14, 19291,995,768 Fesenmaier Mar. 26, 1935 2,325,036 Case July 27, 1943 FOREIGNPATENTS Number Country Date 28,811 Great Britain Dec. 30, 1902 27,657Great Britain Nov. 28, 1910 346,172 France Sept. 12, 1904 168,191Germany May 29, 1903

